Lifting-jack



(No Model.) 2 Sheets-Sheet 1. A. L. STANFORD.

LIFTING JACK.

No. 346,78 Patented Aug. 3, 1886.

- Unrrs STATES FICEG ATENT LlFTlNG-JACK.

EBPECIPICATION forming part of Letters Patent No. 346,783, dated August 3, 1886.

A Application filed January 23, 1886. Serial No. 189,527. (No model.)

To aZZ whom, it may concern.-

Be it known that I, ARTHUR LSTANFORD, acitizen of the United States, residing at XVaukegan, in the county of Lake and State of 1111- nois, have invented certain new and useful Improvements in Lifting-Jacks and Track-Raisers, of which the following is a specification, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

Myinvention consists in the construction and arrangement of parts hereinafter described.

In the accoi'npanying drawings, Figure 1 is a side elevation of my improved lifting-jack or track-raiser. Fig. 2 is a front view, partly in section. Fig. 3 is avertieal transverse section of Fig. 1. Figs. 4, 5, and 6 illustrate details 0 niyinvention.

Similar letters of reference indicatesimilar parts in the respective figures A is the main standard or casting, having an opening, a, in which thelifting-barBslides. This bar B is provided at its lower end with a foot, I), which is recessed, so that the flange of a rail may fit in and under the lifting-bar when the jack is used as a track-lifter. This construction is an important improvement, as the feet can bemade much shorter than usual. The load is also brought nearer the center of the base of the jack, by reason of which, in connection with the arrangement of the fulcrum of the lifting-lever hereinafterdescribed, uneven settling of the jack when used in soft ground isprevented, and thelifting power may be exerted with much better effect. In order to prevent such uneven settling, the location of the centers of the load and the fulcrum of the lifting-lever with reference to the center of the base of the jack, is determined by the following considerations:

If the load rested stationary upon the foot I), the center of support should be directly under the center of the load; but in raising the load weight must be applied to the lever D, thus transferring the load-line to a perpendicular drawn through the pivot (2. As these two conditions are alternating with each other, I so construct the standard as that the center of the supporting-foot is half-way between the two points indicated. I am aware that such a disposition, generally, of these three points is not original with me, but in order to at tain the end for which such disposition is made it is necessary that the centers of both lever-fulcrum and load be brought as near the center of the base of the jack as possible, to accomplish which I recess or offset the lifting-bar at b, and make the lifting-lever forked, as hereinafter described, thus bringing the pointsof application of the power to the clutch-box to the middle of the liftingbar, and bringing the fulcrum of the lifting lever, as well as the load, nearer to the center of the base of the jack, and I thus prevent all tendency to tipping or uneven sinking.

Cast integrally with the standard A is the clutch-box C. \Vithin the box 0, on each side of the bar B, are fitted twouicely-finished steel backing and friction plates, 0 c, of the form shown in Figs. 2 and 6, each pair forming a bearing for a frietion-1'oll,'c.

c 0, thus differing from the construction shown in Patent No. 312,400, granted to me February 17, 1885, and the clutch mechanism contains additional features, which form the subjectmatter of another application (Serial N 0. 189,728) for Letters Patent filed contemporaneously with this application.

Cast with and extending upward from the box 0 are the projections (Z d, which form the bearing for the bolt (1 of the hand-lever D, by which the jack is operated. The upper extension, g g F, forms a guide for the upper part of the lifting-bar,and, in addition, a support on which the flange 6 may rest when the upper clutch is depressed to its fullest extent, thus throwing the clutch out of operation, so that the lifting-bar may descend when the retainingclutch is released, as hereinafter described. Theinner end of the handle D is slotted or cored at d to straddle the liftingbar, and also cored out at d, whereby bearings are provided for the pins f, and also for the pins h, hereinafter referred to.

E is an upper clutch-box, into which is fitted the steel backing-plates 0. (Shown in Figs. 2 and 5.) The friction-plates e 6, also work ing in the upper box, E,-are formed as shown in Figs. 2 and 5, and, in conjunction with the plates or slides a 0, form bearings for the rolls 6.

The clutch box is protected from the wear by the plates The top F of the main standard or casting A is provided with an opening to allow'the passage through it of the bar B and the frie tion-plates c, and is supported by the standards 9, solid with it and the main standard A.

The upper clutch box, IE, is provided with ears h h h h, two being on each side of the opening, through which the lifting bar B passes. To each of these ears h is pivoted at one end a link, h, by a pin, h, each link at its other end being pivoted by one of the pins f to the hand-lever D. It will be seen that by means of this pivotal connection between the clutch-box E and the hand-lever D the clutchbox will always move in a vertical line correspending with the direction of the lift, while the links h, attached to the clutch, will move in the arc of a circle described from the pin (1. The construction is such that the movement in the said are of a circle is equally divided on each side of the vertical line of the lift, the total deviation from the vertical being only about one-eighth of an inch, one-sixteenth of an inch being on each side of the line.

The friction-clutches are so arranged that friction will only be operative in the upper clutch-box, E, when the box is moved upward by the depression of the hand-lever, while the frictional action in the lower box, C, will only occur when the lifting-bar B has a tendency to move downward.

H is a foot or tripping lever pivoted in the main standard at It, its inner arm, is, being forked and extending under the frictionplates 0'. \Vhen it is required to relieve the lifting-bar from the friction in the lower box, 0, the tripping or foot lever H must be depressed, thus lifting the friction plates 0', which project slightly below the box C. When the weight is very great, it is necessary to take the weight upon the upper clutch by depressing the lever D before releasing the lower clutch. Then by raising the lever D till the flanges 6 6 come in contact with the top of the standard the weight will by its own action release the upper clutch and the bar will descend to its lowest point.

The operation is as follows: By depressing the hand-lever D the bar B will be lifted by the rise of the friction-plates in the clutch-box E. On elevating the lever D the strain will be taken from the upperbox, E, and trans ferred to the lower box, 0, the lifting-bar B being held in the position to which it was guide for the lifting-bar, and also as a rest for the flanges e, as described.

2. The combination, in a lifting-jack, of movable and stationary clutches and a lifting bar, with a standard having a stationary clutch-box cast integrally therewith, and an upward extension, substantially as and for the purpose set forth.

3. In a lifting-jack, a standard having the center of its supportingfoot midway between one perpendicular drawn through the center of the load and another drawn through the fulcrum of the operating-lever, combined with friction-elutch devices, a lifting-bar, and a forked lifting-lever, substantially as set forth.

4. The combination of the standard A, extension F, liftingbar B, clutches C an d E, with a liftinglever located between them, releas inglugs e 0, operating against said extension F, and the trip-lever H.

ARTHUR L. STANFORD.

Vi tn esses:

J. I. VEEDnR, P. H. T. MASON. 

